Lock type selector switch



July 5, 1966 e. .1. NEFF, JR

LOCK TYPE SELECTOR SWITCH Filed Oct. 22, 1965 INVENTOR.

GEORGE J. NEFF, JR.

ATTORNEYS.

26 IO u United States Patent 3,259,701 LOCK TYPE SELECTOR SWITCH George J. Nerf, Jr., Erlanger, Ky., assignor to Avco Corporation, Cincinnati, Ohio, a corporation of Delaware Filed Oct. 22, 1965, Ser. No. 501,634 9 Claims. (Cl. 20011) The present invention relates to selector switches of the type involving a rotary contact element angularly positionally adjustable to become encircuited with any one of a plurality of fixed contacts.

Various types of multiple contact switches involving a rotary contact element are well known to those skilled in the art.

It is the principal object of the present invention to provide an improved switch of such a nature that it may be indexed in any one of a plurality of positions and locked therein with a new order of reliability and precision.

Another object of the present invention is to provide such an improved switch which is readily adapted to pluralizing and gauging and accurate positioning and locking of a plurality of rotating elements.

Another object of the invention is to provide such an improved switch in forms equivalent either to a singlepole multi-throw switch or a multi-pole multi-throw switch.

Another object of the invention is to provide an improved switch of the character described which is readily and quickly operated in the field and under the most regorous environmental conditions but which requires the very minimum of operating training.

For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following description of the accompanying drawings, in which:

FIG. 1 is a preferred embodiment of the switchin accordance with the invention, incorporating a plurality of ganged rotors;

FIG. 2 is an exploded view of rotor and stator portions of a single section of the FIG. 1 switch, together with the turning, locking and positioning elements which are common to all of the sections, and

FIG. 3 is a fragmentary cross sectional view as taken along section line 33 of FIG. 1 and looking in the direction of the arrows.

Referring now to FIG. 2, there is shown a stator 11 which carries a plurality of angularly spaced fixed contacts 12, 13, 14, 15 and 16. It will be understood that such contacts may be spaced completely around a 360 degree circular pattern in any manner desired and the number and form of the fixed contacts here shown are not intended to be limiting.

A rotor element 17 is mounted to be selectively adjustably positioned, as desired, precisely to position its spring contact finger 18 to be encircuited with any desired one of the contacts 12-16, etc. Further, it is required that the rot-or 17 be securely locked in that position, but readily manipulable at the will of the operator to assume other positions. While a single contact arm 18 is here illustrated, this again is by Way of illustration and not limitation, because the rotor may bear additional elements and be utilized to control several circuits. The rotor element is keyed to a shaft 19 which will be understood to project through all of the other elements in FIG. 2. The stator 11 further carries a slip ring 9 contacted by finger 8 carried by rotor 17.

The discussion now turns to those elements by reason of which the rotor may be precisely adjustably locked in position. A frontal plate 20 carries an integral bushing 21 in which the shaft 19 is journaled. This plate may be apertured as shown at 22 to provide for visualizing "ice suitable indicia which may be placed on the front of the rotor index gear 23. The periphery of this gear is formed with teeth 24, complementary to the teeth 25 formed in the ring portion of the stator index 26. Inboard of the teeth 25 (i.e., toward the operator) there is formed in stator index 26 an annular inset 27 When teeth 25 mesh with teeth 24, the rotor index 23 is locked in the stator index 26. However, when rotor index 23 is displaced slightly inboard, then rotor index 23 freely rotates in stator index 26. Preferably the gear teeth 25 and the grooves between them are so formed that the grooves slightly converge in the direction from front to rear, and the teeth 24 converge from front to rear in a complementary fashion. The expression front as herein used designates a side toward the front plate 20. The expression rear as herein used refers to a side in the direction of rear plate 7. The purpose of the convergent formations is to facilitate the engagement and final positioning of teeth 24 with respect to teeth 25.

It will be understood that the stator index 26 and the stator 11 are secured together in a rigid framework such that one contact such as 12 corresponds to each position provided by the teeth 24 and 25. Likewise, the rotor index 23 and the rotor 17 are both keyed to the same shaft 19, so that they rotate in unison. The rotor is keyed to the shaft by a formation 5 and is squeezed between ring 29 and spring 28, suitable insulation being provided as required, as will be understood by those of skill in the art.

When the operator desires to change the angular position of the switch 18 and the rotor 17, he simply pulls the shaft 19 toward him, disengaging rotor index 23 from the stator index 26, and then turns the shaft to the position desired, accordingly angularly positioning the rotor index 23 within inset 27. When the desired position is attained the operator releases the keyed shaft 19 and then the shaft and the elements keyed thereto move outboard (away from the operator) so that the teeth 24 and 25 are finally in engagement, providing a lock for the rotor in the precise position desired. In order to pfovide bias which permits the shaft to be pulled inwardly by the operator but automatically returns the shaft outboard on release by the operator, there is a cupped spring element or the like 28. The wings of this cupped spring element bear against bearing plate 10, which is disposed against and behind the stator index 26. This spring is suitably apertured at 36 to permit the passage of the shaft 19 therethrough. Behind the rotor there is a ring element 29, locked in a groove formed in shaft 19. As the shaft 19 is pulled inwardly by the operator, the ring 29 displaces the rotor inwardly and depresses the spring in such a manner as to release the contacts 18 and 8 from their associated contacts on stator 11, thus minimizing wear on those contacts.

Rear end support for the rotor is provided by a rear plate 7 which is formed with a journal 30 through which the shaft projects.

The front plate 20, stator index 26, bearing plate 10, stator 11, and rear plate 7 are disposed in parallelism.

The rear plate 7 and plate 10 and stator 11 and stator index 26 are provided with registering holes such as 31, 32 at their four corners so that a rigid framework may be provided by passing screws forwardly through these holes and securing them to threads such as 33, 34 formed on the rear of plate 20 and near its corners.

In the FIG. 2 embodiment there are only one stator and rotor, but it will be obvious from the foregoing description that additional rotors may be gauged to rotor 17 and additional stators provided so that the switch may be of multiple-throw character. As shown in FIG. 1, behind stator 11 there may be located an additional stator 38, and in the space between stator 11 and stator 38 a spring such as 28 and an additional rotor such as 17. Further sets may be provided as is indicated by the stator 39 in FIG. 1. It will be noted that the FIG. 1 arrangement is secured together by screws such as that indicated at 40, one located near each corner of the structure.

While there has been shown and described what is at present considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined in the appended claims. It will be appreciated, for example, that a push-in arrangement is the full equivalent of the pull-out arrangement herein shown, and such an arrangement is easily accomplished by reversing the stator index in 'such manner that the rotor index may be axially displaced to the rear thereof, positioning each rotor behind its respective stator so that the rotary switch arms touch contacts on the rear of the stator, positioning each cupped spring so that its convex surface tends to urge the rotor forwardly, and then providing a bearing surface rearwardly of the springwhich bearing surface may be the front surface of the next adjacent rearwardly located stator, for example. Finally, in such an embodiment the ring 29 is disposed forwardly of the rotor.

I claim:

1. In a selector switch, the combination of:

a shaft and means for journaling the shaft;

a rotor formed with a switch arm and keyed to the shaft for rotation therewith;

a stator element formed to receive the shaft and having a multiplicity of angularly spaced contacts with any desired one of which the switch arm is to be registered;

and means for accurately performing the registration,

comprising:

a stator index positioned in fixed relation to the stator and having a ring gear formation;

a rotor index formed as a spur gear keyed to said shaft for rotation therewith and adapted to mesh with said ring gear when the spur gear is in axial alignment with said ring gear;

and biasing means for normally urging said gears into axial alignment but yieldable to permit axial displacement of the shaft whereby the shaft and spur gear can be turned;

the gears being formed to define angular positions of registry between said arm and individual ones 'of said contacts.

2. The combination in accordance with claim 1 in which the stator index is formed with a bearing surface and in which the biasing means is a cupped spring having a convex surface bearing against the rotor and tips abutting said bearing surface. r

3. The combination accordance with claim 2 in which the normal order of the elements, proceeding from front to rear, is as follows: rotor index, stator index, cupped spring, rotor, stator.

4. The combination in accordance with claim 3, and locking ring means rigidly secured to said shaft for withdrawing the rotor away from the stator and open-circuiting the switch arm when the gears are axially displaced out of alignment.

5. The combination in accordance with claim 4 in which the means for journaling the shaft comprises suitably apertured front and rear plates.

6. The combination in accordance with claim 5 in which the stator carries a slip ring and the rotor carries a second switch arm adapted to contact said slip ring.

7. The combination in accordance with claim 6 in which the bearing surface is provided by a bearing plate associated with the stator index.

8. The combination in accordance with claim 7 in which there are provided, aft of the first-mentioned stator and in the order indicated: a second cupped spring, a second rotor, and a second stator, thus forming a twosection ganged rotary switch.

9. The combination in accordance with claim 8 in which the group of additional elements enumerated therein is pluralized to form a multi-section rotary switch.

No references cited.

ROBERT K. SCHAEFER, Primary Examiner. 

1. IN A SELECTOR SWITCH, THE COMBINATION OF: A SHAFT AND MEANS FOR JOURNALING THE SHAFT; A ROTOR FORMED WITH A SWITCH ARM AND KEYED TO THE A SHAFT FOR ROTATION THEREWITH; A STATOR ELEMENT FORMED TO RECEIVE THE SHAFT AND HAVING A MULTIPLICITY OF ANGULARLY SPACED CONTACTS WITH AND DESIRED ONE WHICH THE SWITCH ARM IS TO BE REGISTERED; AND MEANS FOR ACCURATELY PERFORMING THE REGISTRATION, COMPRISING: A STATOR INDEX POSITIONED IN FIXED RELATION TO THE STATOR AND HAVING A RING GEAR FORMATION; A ROTOR INDEX FORMED AS A SPUR GEAR KEYED TO SAID SHAFT FOR ROTATION THEREWITH AND ADAPTED TO MESH WITH SAID RING GEAR WHEN THE SPUR GEAR IS IN AXIAL ALIGNMENT WITH SAID RING GEAR; AND BIASING MEANS FOR NORMALLY URGING SAID GEARS INTO AXIAL ALIGNMENT BUT YIELDABLE TO PERMIT AXIAL DISPLACEMENT OF THE SHAFT WHEREBY THE SHAFT AND SPUR GEAR CAN BE TURNED; THE GEARS BEING FORMED TO DEFINE ANGULAR POSITIONS OF REGISTRY BETWEEN SAID ARM AND INDIVIDUAL ONES OF SAID CONTACTS. 